1. Field of the Invention
The present invention relates to a scanning apparatus for scanning a bound document, and more particularly, to a scanning apparatus which can provide a sufficient illumination to a to-be-scanned page of a bound document.
2. Description of the Prior Art
A scanner is utilized for scanning a document and acquiring an image of the document. Because a book is one kind of bound document, a binding area of the book will make a page of the book unable to flatly lie on a scanning window of the scanner when the book is placed on the scanning window, thereby causing distortion to an acquired image. Therefore, a book scanner has been designed so that the portion of the page which is close to the binding area can be scanned without distortion. As shown in FIG. 1, the book scanner has an inclined plane and a scanning window, and an included angle is formed between the inclined plane and the scanning window. FIG. 1 is a side view of a book scanner 100 of prior art. The book scanner 100 includes a scanning window 102, an inclined plane 104, a lamp 106, and a scanning head assembly 108. To explain operating principles of the book scanner 100, a book 110 to be scanned is also shown in FIG. 1. An included angle Θ is formed between the scanning window 102 and the inclined plane 104, so that a to-be-scanned page 110a of the book 110 can flatly lie on the scanning window 102. The lamp 106 is coupled to the scanning head assembly 108, and the lamp 106 will move with the scanning head assembly 108 along the X-axis to provide an illumination to the page 110a. Additionally, in order to provide a sufficient illumination to the portion of the page 110a close to the included angle Θ, the lamp 106 positioned below the scanning window 102 and the inclined plane 104 is designed to have a bent angle to compensate the weaker light intensity at an endpoint of the lamp 106. As a result, the binding area of the to-be-scanned book 110 can have a sufficient illumination. The lamp 106 is usually bent by an angle approximately equal to the included angle Θ between the scanning window 102 and the inclined plane 104. However, the cost of the bent lamp 106 is higher than a straight lamp, and the bent angle of the lamp 106 needs to be customized to agree with the included angle Θ. As a result, the complexity in assembly and cost of the book scanner 100 will be increased. Therefore, how to achieve a light source of the book scanner 100 with a lower cost and provide a sufficient illumination to a page of a book is an urgent issue for the scanner industry.